11. (a) Consider three users and Barker code of six bits each for the users transmitting the signals, introduce noise and near/far problem while transmitting and reconstruct the data in the receiving side providing the proper countermeasures for the complications. (Note: Use CDMA technologies) (Marks 16)
(Or)

12. (a) (i) Sketch the data network in your campus. How many hosts are there and how large is the user population? What is the speed of the access link to the Internet? How so you gain access to the Internet? How much does home access to the Internet costs? (Marks 10)

(ii) Why are so many different identifiers/addresses (e.g. MSISDN, TMSI, IMSI) needed in GSM? Give reasons and distinguish between user- related and system related identifiers. (Marks 6)
(Or)

(b) (i) Consider a mobile user who is migrating from a place to another place, provide him a seamless service by satellite system, also sketch the architecture. (Marks

(ii) Discuss the importance of DECT Protocol Layers. (Marks

13. (a) (i) Detail the time- bounded service on top of the standard DCF mechanism where ad hoc networks cannot use the function. (Marks

(ii) Discuss the PHY frame format of an IEEE 802.11 using the spread spectrum technique which separates by code. (Marks
(Or)

(b) (i) The channel access control sublayer of HIPERLAN offers a connectionless data transfer service to the higher MAC layer. Justify the above statement with related references. (Marks 10)

(ii) Discuss the functionalities and support provided by L2CAP. (Marks 6)

PART A – (10 x 2=20 marks)
1. Differentiate analog modulation and digital modulation.
2. How are guard spaces realized between users in CDMA?
3. What are the general problems of satellite signals travelling from a
satellite to
receiver?
4. Differentiate symmetrical and asymmetrical communication system.
5. What is HIPERLAN?
6. How is mobility restricted using WLANS?
7. What could be quick ‘solutions’ and why don’t they work?
8. What advantages does the use of IPV 6 offer for mobility?
9. Write the advantages and disadvantages of mobile TCP.
10. Define fast retransmit.